1. Field of the Invention:
The present invention relates to a novel halogen-containing s-triazine compounds having two or more s-triazine rings. More particularly, it relates to the use of the compounds and the preparation of the compounds. The s-triazine means 1,3,5-triazine in the specification.
2. Description of the Prior Art:
Organic compounds having high content of halogen atoms have been used as flame retardants for synthetic resins, synthetic fibers or other materials.
The synthetic resins of hydrocarbon type polymers are normally flammable. Accordingly, a flame retarding treatment is preferably applied and in some field, the flame retarding treatment is indispensable.
It has been known for the flame retarding treatment of synthetic resins to use halogen-containing compounds, phosphorus-containing compounds, antimony compounds, nitrogen-containing compounds etc. The halogen-containing compounds have been especially effective. The flame retarding property is higher depending upon increase of halogen content in the halogen-containing compounds. However, it is not always effective as the flame retardants to have high halogen content. It is important to have various physical and chemical characteristics such as high miscibility to the synthetic resin and suitable melting point and high thermal stability and high weather-proofing property and not to deteriorate the synthetic resin etc.
It has been known to use halogen-containing s-triazine compounds having single s-triazine ring as flame retardants. For example, tris-(2,4,6-tribromophenoxy)-s-triazines have been disclosed in French Pat. No. 1,566,675 published on May 9, 1969 and tris-(polybromophenoxy)-s-triazines as flame retardants for polystyrenes and polyolefins have been disclosed in U.S. Pat. No. 3,843,650 and published on Oct. 22, 1974, and tris-(polyhalophenoxy)-s-triazines as flame retardants for polyolefins, polystyrenes, ABS, PVC etc., have been disclosed in Japanese Unexamined Patent Publication No. 25232/1972 published on Oct. 19, 1972.
These tris-(polyhalophenoxy)-s-triazines have high flame retardancy, however, they have not enough thermal stability and they cause bleed-out when they are blended to the synthetic resins.